Narrow Pigtoe

Narrow pigtoe has a triangular to square shape with a black to reddish-brown color. Narrow pigtoe reaches approximately 75 millimetres (3.0 in) in length as an adult. Its shell is moderately thick with a white- to salmon-colored interior. Narrow pigtoe also has a rainbow pattern near the base of the interior shell. Narrow pigtoe differs from other Fusconaia species in that it has a slightly different color of shell. Furthermore, narrow pigtoe has a different geographical range, distinctive from other Fusconaia species. Lastly, narrow pigtoe uses distinct fish species to mature. See more on this in the Life History and Ecology sections.

For most freshwater bivalve mussels, the habitat involves slow to moderate currents in small to medium sized rivers or creeks. The narrow pigtoe embeds itself in the ground (which often includes sand, gravel, and silt) as long as it is stable and not disturbed. As stated before, the narrow pigtoe's habitat is also reliant on whether or not its host fish species are present in the area. The narrow pigtoe is sensitive to ecological disturbances and must have little pollution, good water quality, and a secure habitat to grow successfully.

Narrow pigtoe siphons water into its shell and across the gills to feed. Narrow pigtoe consumes detritus (which is disintegrated organic debris), algae, diatoms, and bacteria. Adults are filter feeders and feed through siphoning water into the shell. Juveniles burrow beneath the ground and are pedal (foot) feeders. In other words, they bring food particles that adhere to the foot inside the shell for ingestion. Foot feeding occurs until the structures for filter feeding are fully developed. Larval stages feed by stealing nutrients from the host fish.

Little is known about the narrow pigtoe's current life history. Narrow pigtoe typically undergoes reproduction from May to July. However, pregnant females have been found as early as March and as late as October. Narrow pigtoe is known as a short-term brooder, meaning narrow pigtoe will usually develop their eggs for 2–6 weeks. Generally, freshwater mussels have thousands of offspring to ensure some larvae will grow up and become adults. Males release sperm into the water, and females receive the sperm through special feeding tubes called siphons. The eggs then become fertilized inside the shell of the female. Inside of the shell, the fertilized eggs grow until they reach a mature larva stage. The larvae then attach to host fish and live as parasites feeding off the fish. The feeding helps them transform into juvenile mussels. Juveniles then drop from their respective fish and sink to the bottom of the body of water to mature into adults. Being a freshwater mussel species, it is thought that narrow pigtoe also reproduce and live as such. Narrow pigtoe's geographic location relies on the host fish.